18 amazing amplifiers are at the core of HD amp modeling. Take a closer look at a few of the star players. How much do you know about each one?

Gibson® EH-185

With its hot "microphone" input and a well-worn 12" field-coil speaker, the Gibson® EH-185 combo of 1939-'42 has become a favorite of blues guitarists and studio players alike. This was Gibson's top-of-the-line amp of the early electrified jazz age, and nothing else quite nails the round, warm, woody tone and easy breakup of its octal preamp stage and dual-6L6 output stage.

The EH-185 makes a surprisingly versatile voice for sculpting anything from vintage jazz tones to raw rock 'n' roll when cranked up, and sits beautifully in a full-band mix, both live and in the studio. Seminal jazzer Charlie Christian is believed to have moved up to an EH-185 combo before his death, about the same time that he stepped up from his original Gibson® ES®-150 guitar to an ES®-250. Current players like Josh Homme have been spotted playing this little beauty on some big stages.

After almost 4 months of daily Internet searches, Line 6 finally located and procured a Gibson® EH-185 for its HD modeling collection. The immaculate specimen was boxed and shipped like a crown jewel and arrived safe and sound from its native Mississippi. Like kids at Christmas, anxious Line 6ers gathered 'round for the great unveiling. After some lightly rejuvenating spa treatment from one of LA's top amp techs, the EH-185 was modeled with incredible results.

Park 75

Manufactured by Jim Marshall from the mid '60s until the late '70s as a means of circumventing an exclusive English distribution deal for the amplifiers bearing his name, Park amps have become legendary. But none has attained the mythical status of the beefy Park 75. Although they were usually based loosely on circuits used in classic Marshall® amps, Park models were often given clever new twists, such as the increased front-end gain in the 75 and the use of military-grade KT88 output tubes rather than the traditional EL34s. Add it all up, and it's a sizzling, crunchy plexi-style tone like nothing you've ever heard, equally adept at classic British blues-rock and contemporary grind.

Line 6 snatched up its Park 75 during an amplifier recon trip around Southern California. On the hunt for another piece of gear, Line 6ers noticed the Park 75 peeking out from behind other amps. A rare find (according to legend, only 300-400 were ever made), the amp was in great shape and its cab was complete with original Fane speakers. A short test-drive was all it took for the recon group to fall in love with the vintage vibe that sounded as good as it looked.

Dr. Z® Route 66

One of the most original, and most successful, designers and manufacturers in the contemporary "boutique" scene, Dr. Z is known for establishing new tonal templates, rather than cloning the vintage standards. The popular Route 66 is perhaps the best case in point: based around a pair of KT66 output tubes (a ruggedized, military-spec version of the 6L6), with an EF86 pentode in the preamp, the Route 66 manages to make the most of high-end "ultra-linear" output transformers that are popular in the tube audio world, but have foiled guitar amp makers for decades. The result is an amp that achieves an extremely full-bodied, "milkshake thick" overdrive when pushed, without ever losing its impressive clarity and definition. In short, a new and original classic.

Divided by 13 JRT 9/15

Divided by 13 is a relative newcomer to the "boutique" amp market, but one that brings several unique twists to its designs, by referencing some of the more unusual tube complements of the past as well as combining unexpected feature sets-all in hand-build amplifiers of the highest quality. The company's JRT 9/15 is a perfect example: using a pair of 5879 pentode preamp tubes (best known for their use in the Gibson® GA-40 Les Paul Amp of the '50s), Divided by 13 creates two differently voiced but blendable channels for a simple yet incredibly versatile front end. Running this through one of two switchable output stages built into the same amp - a pair of 6V6GTs in class A for 9 watts, or a pair of EL84s in class AB for 15 watts - further augments this amp's voice exponentially. The result is a palette of tones that remind you of the best American "tweed" and classic British amps, while somehow sounding entirely unique throughout their range.

ENGL® Fireball 100

Designed to redefine the stereotypical "shred" sound and dial in a more musical lower-midrange and bass response, the ENGL® Fireball 100 has become one of the new standards of contemporary rock and metal. Using a quad of 6L6 output tubes for mammoth lows and gut-thumping punch, and four 12AX7 preamp tubes for scorched-earth gain levels, the Fireball 100 nevertheless brings great refinement and articulation to this aggressive genre, boasts surprising versatility, and has earned its keep in the rigs of several cutting-edge shredmeisters.

Supro® S6616

This little oddball might seem an unlikely candidate for "classic amp" status but its distinctively fat, thick, organic smoothie of tone (rumored to be the source of some classic Zep tracks) has made it a go-to tool in studios around the world.

The Supro® S6616 of the late '50s and early '60s - manufactured by Valco in Chicago - has a single-ended 6V6 output stage, unusual preamp circuitry, and an oval 6"x9" speaker. Wind it up and the S6616 offers juicy, brown overdrive that can sound like a raging stack when mixed with the track, yet with a character all its own. Reined in to clean volumes, it is beautifully spanky and crisp. And at all levels that 6"x9" speaker yields nodes and peaks that contribute to that unusual and distinctive sonic voice that has come to be known as the Supro® S6616 sound.

Fender® "tweed" Bassman®

Simply the crème de la crème of vintage amps from the '50s, the Fender® 5F6-A Bassman® combo with 4x10" Jensen® speakers established a template for amp design that has been reflected in countless models from other makers through the years, as well as setting a standard for tone that many players would say has never been bettered.

The long-tailed pair phase inverter and fixed-bias class AB output stage with a pair of 6L6GC tubes make the Bassman® a firm, bold performer, with gutsy, multi-dimensional clean tones that scream vintage country and rock 'n' roll. Wind it up, though, and it transforms into a creamy, expressive blues and rock machine, with a complex voice that's enhanced by a lively solid-pine cab with "floating" 4x10" speaker baffle. Its 5AR4 tube rectifier aids in its outstanding dynamic response, and it boasts great touch-sensitivity thanks to a highly interactive three-knob "cathode-follower" tone stack.

As Buddy Guy, Bruce Springsteen, Jimmy Vaughan, and so many others would tell you, when you're talking vintage amps, the Bassman® really is ground-zero for big combo tone.